 namespace local = ""
 namespace inh = inherit
 
 include "flat.rnc"
 {
    book-element = 
       element book
       {
          attribute id { text },
          attribute available { text },
          isbn-element,
          title-element,
          description-element,
          author-element*
       }
 }
 
 description-element = element description { text }
